java.lang.NumberFormatException: null When starting AdminServer

java.lang.NumberFormatException: null

Symptoms

The following  exception appears on startup on the admin server. The admin server then fails to start up.

####<17-Jul-2009 10:24:02 o'clock GMT> <Critical> <WebLogicServer> <silvermoon> <AdminServer> <Main Thread> <<WLS Kernel>> <> <> <1227111442502> <BEA-000386> <Server subsystem failed. Reason: java.lang.NumberFormatException: null
java.lang.NumberFormatException: null
at java.lang.Integer.parseInt(Integer.java:415)
at java.lang.Integer.parseInt(Integer.java:497)
at weblogic.ldap.EmbeddedLDAP.validateVDEDirectories(EmbeddedLDAP.java:1035)
at weblogic.ldap.EmbeddedLDAP.start(EmbeddedLDAP.java:212)
at weblogic.t3.srvr.SubsystemRequest.run(SubsystemRequest.java:64)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:209)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:181)

Cause

This is something that happens infrequently and is the result of a corrupted file in the embedded LDAP. It can be caused when your system is starting to run low on disk space 

Solution

There are two ways to fix this issue:
1) Delete the file /servers/<server_name>/data/ldap/config/replicas.prop